Acute lung injury (ALI) is a life-threatening condition that occurs in patients triggered with complex factors, contributing to multiple organ dysfunction and mortality. Therefore, it is crucial to seek novel targets for treating ALI. To investigate the effects of Potentilla anserina L. polysaccharide (PAP) on ALI and associated damage to the intestinal mucosal barrier induced by lipopolysaccharide (LPS), ALI mouse model was adopted. Mice were intraperitoneal injection of LPS, with or without PAP., then serum, lung, spleen, small intestine, and bronchoalveolar lavage fluid (BALF) samples of mice obtained were used to discuss the treatment of PAP on ALI and relevant organ damage. Meanwhile, the underlying signal pathway was searched from GeneCards and DisGeNET databases, and then verified it by western blot. These results indicated that PAP effectively reduced inflammatory levels in LPS-induced ALI and associated intestinal mucosal barrier impairment, as well as the M1 macrophage immune response by activating the Rap1 signal pathway. These results suggested that the medicinal herb PAP is a therapeutic potential anti-inflammatory agent for ALI and relevant organ dysfunction.